1. Field
The present disclosure relates to nanoparticles, and more particularly, to nanoparticle polymers and methods of preparing nanoparticle polymers.
2. Description of the Related Art
A nanoparticle polymer refers to an assembly of at least two nanoparticles linked to each other by a linker. A nanoparticle polymer may have characteristics different from those of isolated nanoparticles. For example, electronic interactions between adjacent nanoparticles in a nanoparticle polymer are known to be different from those of isolated nanoparticles (see Xiangxing Xu, et al., “Assembly and Separation of Semiconductor Quantum Dot Dimers and Trimers,”, J. Am. Chem. Soc. 2011, 133, 18062-18065).
Quantum dots, a type of nanoparticles, are nanoparticles of group II-VI semiconductors, group III-V semiconductors, group I-III-VI semiconductors, or group IV-VI semiconductors. Due to the quantum confinement effect, quantum dots may exhibit high light-extinction performance or high light-emission performance. Accordingly, quantum dots are expected to hold promise for use in photoelectric devices such as, for example, light-emitting devices (LEDs), lasers, or solar cells. In most of these fields of application, assemblies of quantum dots, rather than isolated quantum dots, are required (see Rolf Koole, et al., “Electronic Coupling and Exciton Energy Transfer in CdTe Quantum-Dot Molecules,” J. Am. Chem. Soc. 2006, 128, 10436-10441).
A related art nanoparticle polymer may be prepared by using a linker to connect nanoparticles that are passivated by an organic ligand. For example, in the article “Electronic Coupling and Exciton Energy Transfer in CdTe Quantum-Dot Molecules,” by Rolf Koole, et al., mentioned above, a CdTe quantum dot dimer is disclosed in which two CdTe quantum dots passivated by allylamine are linked via 1,6-hexanedithiol. As another example, in the article “Assembly and Separation of Semiconductor Quantum Dot Dimers and Trimers, by Xiangxing Xu, et al., mentioned above, a quantum dot oligomer is disclosed in which CdSe/CdS/ZnS core-shell quantum dots passivated by oleic acid/oleylamine ligands are linked by terrylene diimide.
However, in such related art nanoparticle polymers obtained using organic ligands and organic linkers, charge transport between adjacent nanoparticles is impossible.